Sliding door mechanism



March 6, 1956 NLEVINE 2,736,931

SLIDING DOOR MECHANISM Filed Nov. 1, '1954 2 Sheets-Sheet 1 20 Fig. I

IN VEN TOR.

BYMK M March 6, 1956 vm I 2,736,931

SLIDING DOOR MECHANISM I Filed Nov. 1, 1954 2 Sheets-Sheet 2 Fig. 2

United States Patent SLIDING DOOR MECHANISM Nathan Levine, Newton, Mass., assignor to Babcock-Davis Associates, Inc., Boston, Mass., a corporation of Massachusetts Application November 1, 1954, Serial No. 465,983

2 Claims. (Cl. 20-19) The present invention relates to sliding doors and more particularly to sliding doors which are completely closed at sides, top and bottom when closed.

The invention is especially concerned with doors for X-ray rooms in which the door is completely closed to prevent passage of radiation during exposure. This requires that the door run in a slot in the floor, but when the door is open the slot prevents free passage of tables, beds and the like into or out of the room and also tends to cause accidents to nurses and attendants walking through the passage.

The object of the present invention is to provide a simple construction whereby the door when open automatically provides a continuous load-bearing surface across the slot.

With this object in view the present invention comprises the door assembly hereinafter described and particularly defined in the claims.

In the accompanying drawings Fig. 1 is an elevation of the preferred form of door assembly.

Fig. 2 is a detail sectional elevation showing the device with the door in closed position.

Fig. 3 is a section on line 33 of Fig. 2.

Fig. 4 is a sectional elevation similar to Fig. 2 but showing the parts in the position assumed when the door is partly open.

Fig. 5 is a section on line 5--5 of Fig. 4, and

Fig. 6 is a top plan view of the load-supporting means.

In the illustrated embodiment of the invention a door 10 is arranged to slide with respect to a wall 12, the door being conveniently mounted for sliding as indicated by the rails 14 and wheels 16 above the door. The wall is provided with a door frame which overlaps the door at both sides and top when the door is closed. In Fig. l the ceiling 18 and floor 20 are also shown.

When the assembly is used for an X-ray room it is necessary to provide for escape of radiation not only around the sides and top, but also under the bottom of the door. The door is arranged to slide in a slot formed by a channel 22 received in the floor below the surface thereof. The channel carries sills 24 extending substantially the full length of the channel and welded to the interior surfaces thereof. As indicated in Fig. l, the length of the channel is approximately twice the width of the door.

The door is provided with a bracket 26 carrying vertically journalled rollers 28 adapted to engage the vertical walls of the sills 24 and thus position the door properly for sliding motion.

Secured externally to each side of the channel is an angle iron 30. Each angle iron has a horizontal portion 32 overlying its corresponding sill 24. As shown in Figs. 3 and 5, the flat portions 32 are flush with the surface of the floor 20. The ends of the channel are closed by vertical wall pieces 34 to permit casting of the concrete around the channel.

2,736,931 Patented Mar. 6, 1956 Near opposite ends of the channel are mounted sprocket wheels 35, each being mounted on a shaft 36 journalled in a U-shaped insert 37 fixed to the end wall 34 of the channel. A continuous chain 38 runs around the sprocket wheels and is connected at its ends to the door. Mounted on separate links of the chain are slats 38, the ends of which are adapted to ride on the sills 24 as shown in Fig. 5. Also, as shown in Fig. 5, the slats 38 are substantially flush with the horizontal portions of the angle irons 30 which in turn are flush with the floor.

When the door is closed, the parts are in the position shown in Figs. 1 and 2. At that time all of the slats 38 except a few at the right hand end of the door are in the bottom of the channel. As the door is opened, the chain is pulled by the door in such a manner that the slats ride over the sills 24 as indicated in Fig. 4. The sills and the surfaces 32 provide a substantially continuous load-bearing surface when the door is open. This load-bearing surface is flush with and continuous with the floor so that a person may readily walk into or out of the room without tripping and there is no interference with the wheeling of beds, tables or chairs into or out of the room. When the door is closed the door space is completely sealed against any escape of radiation around the door.

Having thus described the invention, I claim:

1. A sliding door assembly comprising a floor having a longitudinal recess, a channel received in the recess below the floor level, a door frame, a door Which, when closed, is covered by the frame on sides and top, the bottom of the door being received in the channel in all positions of the door, means for supporting the door for sliding movement, sprocket wheels at opposite ends of the channel, a chain in the channel and running around the sprocket wheels and attached at opposite ends to the door, load-supporting slats connected with the separate linksof the chain, the separate slats extending across the channel and being uniformly spaced along the chain, sills mounted on the interior walls of the channel and serving as supports for the ends of the slats, and flat pieces partially overlying the sills and flush with the slats to provide a substantially continuous load-bearing surface over the channel when the door is open.

2. A sliding door assembly comprising a floor having a longitudinal recess, a channel received in the recess below the floor level, a door frame, a door which, when closed, is covered by the frame on sides and top, the bottom of the door being received in the channel in all positions of the door, means for supporting the door for sliding movement, sprocket wheels at opposite ends of the channel, a chain in the channel and running around the sprocket wheels and attached at opposite ends to the door, load-supporting slats connected with the separate links of the chain, the separate slats extending across the channel and being uniformly spaced along the chain, sills mounted on the interior walls of the channel and serving as supports for the ends of the slats, and angle pieces secured to the exterior walls of the channel and having portionspartially overlying the sills, said overlying portions and the slats being flush with each other and with the floor surface to provide a substantially continuous load-bearing surface over the channel when the door is open.

References Cited in the file of this patent UNITED STATES PATENTS 2,339,315 Alio Jan. 18, 1944 2,599,747 Craigon June 10, 1952 

